Oil radiator



Dec. 3, 1940. J, D E 2,223,662

OIL RADIATOR Filed Nov. 10, 1939 ZSheets-Sheet 1 INVENTOR Jase oh D.Lear ATTORNEY Dec. 3, 1940. J LEAR 2,223,662

- OIL RADIATOR Filed Nov. 10, 1939 2 Sheets-Sheet 2 INVENTOR Jose 2hDLear ATTORNEY Patented Dec. 3, 1940 OIL RADIATOR Joseph D. Lear,Buflalo, N. Y., assignor to Fedders Manufacturing Company, Inc.,BuffalmN. Y.

Application November 10, 1939, Serial No. 303,813

' 4 Claims. (Cl. 257-2) This invention relates to oil cooling radiatorswhich are adapted for use with internal combustion engines.

The invention is particularly directed to oil radiators of theself-heating type,'whereinhot entrant oil is utilized to preheat thecore whenever the oil in the core becomes too viscous and cold to beforced freely therethrough. In the present invention it is proposed bothto simplify and to reduce the weight of the cooler by a novel corestructure including a single tortuous channel arrangement through whichthe oil may selectively flow either transversely or longitudinal ly,depending upon temperature conditions in the cooler and a respondingcircuit control instrumentality which is included in the unit. Inattaining this result, the cellular structure of the core isprogressively modified along said passage so that the core elementsthemselves form heating zones for succeeding groups of cells.

Thus the present invention provides a selfheating core which does notrequire a heating jacket or like preheating structure; as is typical ofprior art coolers. As a result, it has been found that the inventionpermits an appreciable saving in space, material and assembly cost, andincreased aerodynamic and thermal efllciency in active use.

Other advantages and features of the invention are more fully set forthin the specification and accompanying drawings, wherein:

) Fig. 1 is a diagrammatic view of an oil cooling system for an internalcombustion engine;

Fig. 2 is aside view of the oil cooler of the invention with thefittings and adjoining portions of the core shown in section;

Fig. 3 is a section on the line 3-3 of Fig. 2;

Fig. 4 is a fragmentary section on the line 4-4 of Fig. 2;

a Fig. 5 is a fragmentary perspective view of the tube group located inthe inlet portion of the tortuous channel of the core of Fig. 2;

Fig. 6 is a cross section through the cooler of a further embodiment ofthe invention.

A typical oil supply andcooling system is' shown in Fig. 1, wherein theengine l operates an oil cooler supply pump H, which receives oil fromthe engine sump through a conduit l2 and delivers it to 'the oil cooler|3 through a conduit l4. After being cooled, the oil is directed fromthe cooler back to the engine through a conduit A by-pass conduit I6,including a by-pass valve I1, is arranged between the outlet of the pumpand the engine sump, and it provides a safety device which protects boththe pump and the cooler l3 from excessive head pressures which mayresult from blocking of the circuit by highly viscous cold oil. Ifdesired, the pump may be used solely for supplying the cooler, and asecond pump 20 provided for supplying the bearings of the engine Ill.

The oil cooler |3 includes a core 2| and an enclosing casing 22therefor, which casing is most advantageously of cylindrical form. Thecasing is provided at one end with an inlet port 23 and at the oppositeend with an oil outlet port 24 and approximate relief outlet port 25. Itis proposed to form a single tortuous passage or channel 26 within thecooler, through which the oil may be directed from the inlet port 23 tothe outlet port 24, and such passage is formed by a bafie plate 21extending radially from the casing 22 toward the center of the core anda spaced parallel plate 28 whose. extremity is formed with a reentrantbent portion 29. The inlet port 23 is located between the plates 21 and28, and thus oil may be directed therefrom toward the center of thecooler, and about the bent portion 29, whence it is guidedcounter-clockwise within the casing 22 until it emerges from the outletport 24, which port (Fig. 4) is disposed immediately beneath the plate28.

It is not intended to limit the invention to the shape and proportionsherein shown, and it will be hereinafter obvious that both the coolerand the channel 26 therein may take other geometrical forms which aretoo numerous to describe. In this connection, it will 'be noted that thebaille plate 21 may be eliminated entirely in smaller forms of coolers.

The core 2| is preferably fabricated of individual elements, which inFigs. 2 to 5 consist of elongated tubes 30 and 3| of the same diameterbut formed with large and small hexagonal heads 32 and 33 respectively.The tubes 30 are all located in a group A at the inlet end of thechannel 26, while the remainder of the available space within the casingis packed with the tubes 3|. To reduce the soldering operations andfacilitate assembly, the marginal tubes of the group A may be formedwith pentagonal heads 32a, so that when this group is assembled innested relation (Fig. 5), planar surfaces 34,35 and 36 are presented tothe bafile plates 21 and 28, and to the adjacent tubes 3|. Similarly,the marginal tubes 3| may be formed with similar special heads 33a.

After the tubes are arranged within the casing 22 in nested relation,the adjoining surfaces of the heads are soldered together, and theperiph- 55 eral tube heads are also soldered to the casing 22. Thisseals the spaces between the tubes into one locular mass within theconfines of the casing 22. The interior tube passages provide aplurality of parallel conduits through which air may be directed throughthe core. It will be noted that the bent portion 29 of the bafile plate28 is corrugated, as indicated by the numeral 28a, and further that itis of a general hexagonal formation. This permits the heads 33 of thetubes 3| to be nested therewith in perfect registry.

Inlet and outlet fittings 31 and 38 respectively are soldered to thecasing 22, and they communicate with the previously mentioned conduitsl4 and I5. The outlet fittings 38 contain two passages 40 and M, whichoverlie the outlet port 24 and relief port 25 respectively. A transversevalve chamber 42 opens into the passage 40 and it is formed with a valveseat 43 leading into the passage 4|. A valve 45 is positioned on theseat ,43, and it is provided with a stem 46 which is slidably carried ina nut member 41. The nut member is removably positioned in a tapped hole48 in the fitting 38, and it carries a spring 50 which engages the valve45.

In the operation of the oil cooling system, it will be apparent that auniform pressure will be maintained therein through the operation of thevalve-controlled by-pass circuit 15 about the pump ll. As a result, theoil cooler will be protected from rupturing pressures when the oiltherein is in a highly viscous state. Under such conditions, when theoil enters the cooler through the conduit l4 and inlet port 23, itspassage through the tortuous channel 26 will be blocked by thick, coldoil lying between the tubes 3|. Thus, the oil, in following the path ofthe least resistance, will flow axially along the entrance tubes 30 tothe relief port 25. The valve accordingly will be forced open, and theoil will flow through the seat 43 and valve chamber 42 to the outletconduit [5. It will be noted that the relatively wide spacing betweenthe tubes 30 provides a plurality of axial passages of generousproportions which offer only a small resistance to the relief flow ofoil. The oil, in passing axially through the cooler, will give up someof its heat to the battle structure and to the adjoining portions of thecold and stagnant main oil body. It will also be observed that the heatexchange action is accompanied by a physical action, in which the warmmoving oil directly contacts the cold oil in a wiping or looseningefi'ect. Thus, the cold oil in the remote spaces of the tubes 3| will becleared away and the warm oil flow will progressively advance to thecenter of the core, where its heat exchange action with the tubes 30will be most effective.

As the engine warms up, the transient oil will become warmer and lessviscous, and as a result its velocity through the cooler will becomegreater and its heat exchange ability more effective. Thus the cold oilin the cooler will be rapidly heated, whereupon normal flow through thetortuous channel 26 will be instituted and the casing 60 contains tubesSI, 62 and 63 ofprogressively greater diameter, whose heads 61a, 62a,63a are of identical proportions. Bafile plates 64 and 65 form atortuous channel 26a disposed similarly to that of the first embodiment,and it will be observed that such plates are corrugated as indicated bythe numeral 66, so that the tubes and plates may be nested withoutspecial assembly provisions. The tubes are arranged in groups with thesmallest tubes 6| disposed adjacent the entrance ofthe channel 26a, andthe next largest tubes 62 arranged adjacent to the tubes 6|. Thus itwill be seen that the relatively large spaces between the tubes 6|provide an axial passage for the oil in its initial relief flow from thefitting 31 to the fitting 38, while the intermediate spaces between thetubes 62 provide for easy communication with the remaining tubes 63after the warming progresses to the center of the core.

It will be apparent to those skilled in the art that it is intendedherein to disclose a principle of construction wherein the core itselfis devised with a preheating section. Thus the invention is not intendedto be limited to specific forms of valves, casings and tube elements,except as set forth in the accompanying claims.

I claim:

1. An oil cooler comprising a cellular core formed with parallel airpassages and a thermally related locular mass of internal oil passages,a casing sealing open portions of the oil passages, baffle means securedto the casing'and extending into the oil passages to form a tortuouschannel therein, spaced inlet and relief ports formed in the casing andboth communicating with one extremity of said tortuous channel, anoutlet port formed in the casing and communicating with the remainingextremity of said channel, the oil passages in the first named extremityof the tortuous channel being formed and proportioned to offer lessresistance to the passage of viscous oil than the remaining passages,whereby oil may flow axially from the inlet to the relief ports whenflow through the channel is blocked by cold oil, and valve controlledmeans responsive to pressure conditions within the core for connectingsaid relief and outlet ports.

2. An oil cooler comprising a plurality of elongated tubes havingenlarged polygonal heads at each extremity, means securing the headstogether in interengaging relation to form a core having a locular massof internal oil passages, a casing enclosing the tubes and sealingtherein the exposed portions of the tube passages, bafiie means securedto the casing and extending into the oil passages to form a tortuouschannel therein, spacedinlet and relief ports formed in the casing andboth communicating with a common extremity of said tortuous channel, anoutlet port formed in the casing and communicating with the remainingextremity of the channel, the heads of the tubes at the inlet extremityof the channel being larger than the heads of the remaining tubes toprovide increased tube spacing at such portion of the core, whereby oilmay flow axially along the tubes when flow through the means securingthe heads together in interengaging relation to form a core having alocular mass of internal oil passages, a casing enclosing the tubes andsealing therein the exposed portions of the tube passages, bafile meanssecured to the casing and extending into the oil passages to form atortuous channel therein, spaced inlet and relief ports formed in thecasing and both communicating with a common extremity of said tortuouschannel, an outlet port formed in the casing and communicating with theremaining extremity of said channel, ,the tubes at the inlet extremityof the channel being of lesser diameter than the remaining tubes,whereby oil may flow axially along the tubes from the inlet to therelief ports when flow through the channel is blocked by cold oil, andvalve controlled means responsive to pressure conditions within the corefor connecting said relief andoutlet ports.

4. An oil cooler comprising a plurality of elongated tubes havingenlarged and similarly-proportioned heads at each extremity, meanssecuring the heads together in interengaging relation to form a corehaving a locular mass of internal oil passages, a corrugated battleplate disposed between the tubes and having its extremities engagedbetwen the heads of the tubes, said plate forming a tortuous oil channelwithin the core, a casing enclosing the tubes and sealing'therein theexposed portions of the oil passages, spaced inlet and relief portsformed in the casing and both communicating with acommon extremity ofsaid tortuous channel, an outlet port formed in the casing andcommunicating with the remaining extremity of said channel, the tubes atthe inlet extremity of the channel being of lesser diameter than theremaining tubes, whereby oil may flow axially along the tubes from theinlet to the relief ports when flow through the channel is blocked bycold oil, and valve controlled means responsive to pressure conditionswithin the core for connecting said relief and outlet ports.

JOSEPH D. LEAR.

